test please delete

[PRC1964]

Total synthesis of tubulysin U and V.
Dömling A, Beck B, ..., Lu Y, Wessjohann LA
Angew Chem Int Ed Engl 2006 Nov 6 45(43):7235-9

"Tubulysins are among the most potent tubulin-modifiers known, and they..."
Evaluated by Faculty of 1000 Biology member Peter Wipf (University of Pittsburgh, United States of America)

[PRC1964]

Going from u to v or from v to u?
Time Limit:2000MS Memory Limit:65536K
Total Submit:2925 Accepted:464

Description
In order to make their sons brave, Jiajia and Wind take them to a big cave. The cave has n rooms, and one-way corridors connecting some rooms. Each time, Wind choose two rooms x and y, and ask one of their little sons go from one to the other. The son can either go from x to y, or from y to x. Wind promised that her tasks are all possible, but she actually doesn't know how to decide if a task is possible. To make her life easier, Jiajia decided to choose a cave in which every pair of rooms is a possible task. Given a cave, can you tell Jiajia whether Wind can randomly choose two rooms without worrying about anything?

Input
The first line contains a single integer T, the number of test cases. And followed T cases.

The first line for each case contains two integers n, m(0 < n < 1001,m < 6000), the number of rooms and corridors in the cave. The next m lines each contains two integers u and v, indicating that there is a corridor connecting room u and room v directly.


Output
The output should contain T lines. Write 'Yes' if the cave has the property stated above, or 'No' otherwise.



Sample Input
13 31 22 33 1



Sample Output
Yes

Source
POJ Monthly--2006.02.26,zgl & twb

[PRC1964]

The letters u and v can cause some confusion, partly because they are not differentiated graphically, even in languages other than Latin which employ different sounds for them. The other main problem is their capacity for disguise amongst other letters in both formal Gothic book hands and cursive scripts. A related issue is how to render them in transcription. Do you modernise the spelling, render them all as u, or transcribe them as u or v depending on what they actually look like? It would seem that even among the most scholarly of authors, different conventions are adhered to and I guess the main thing is to decide your own policy and be consistent with it. I have tended in these exercises to just use u when it is Latin, but that is because the purpose of this website is to teach the reading of scripts, so I am being very literal. What you see is what you get. If I was doing a literary edition, I think I would use u and v in their modern sense so that they didn't distract from the reading. On the other hand, with English and French I tend to do it for sense rather than precise form. No doubt the issue could be debated long and earnestly.

[PRC1964]

The History of u and v (2) In the document hands and later cursive book hands, the forms of u and v remain similar, but the less formal method of writing without little adornments to the tops and bottoms of vertical elements can reduce the letters made from minims to a series of incomprehensible wiggles, especially in fully cursive hands where the letters are connected. This is not so apparent when the letters are dissected out as shown here. It becomes increasingly common to use a different form of the letter, whether as a vowel or consonant, at the beginning of a word. As this is a relatively uncommon occurence, the absence of this form from a specific example does not necessarily mean that it does not occur in the script type. This occurs in both Latin and vernacular languages. Calligraphic flourishes added to the letter when used at the beginning of a word can add to the confusion.

[PRC1964]

U & V Intertrade Co., Ltd.

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Address:49/3-4 Moo 2 Chaengwatana Road Bangtarad, Pak Kret, Nonthaburi, 11120, ThailandTel: 662-9621646Fax: 662-9621014

Import Merchants or Agents

[PRC1964]

THE UPPERCASE U-V PROBLEM

Blackletter

Capture all blackletter forms (including variant forms in textura and rotunda (which mostly resemble "U"), and bastarda (which mostly resemble "V") as V

[PRC1964]

Italic

In italic fonts, distinguish between three forms: "U" "V" and "&V;". Capture the standard (but uncommon) rounded U form as "U"; the pointed "V" form as "V" and the 'swash' form as "&V;"

[PRC1964]

Roman

Roman U and V rarely cause problems. The only possibly ambiguous form is probably the plain rounded U without any vertical descender extending to the baseline on the right side. Treat this as "U".

[PRC1964]

APPENDIX: Lower-case u/v

Blackletter and Fraktur

There are distinct forms for "u" and "v". Capture the u as u and the v as v.

[PRC1964]

OTHERS

If you do not recognize the typeface, or if the letter is exceptional, capture it as U or V depending on its general appearance.